1. Field of the Invention
The present invention relates to a seat cushion pumping device for a vehicle which has an improved construction for allowing a height of a seat cushion to be adjusted in conformity with a body figure of an occupant.
2. Description of the Related Art
Vehicle seats function to support occupants in a sitting position. Generally, vehicle seats are divided into a separation type seat which is used as a driver""s seat and a front passenger seat to allow one person to sit thereon and a bench type seat which is used as a rear passenger seat to allow several persons to sit thereon at the same time.
A seat is composed of a seat cushion and a seat back. The seat cushion and seat back surround their respective frames which are made of metallic material to form skeletons of the seat cushion and seat back. The seat cushion and seat back are brought into contact with the body of an occupant to render riding comfort and ensure a correct sitting posture.
The seat is supported by a seat rail assembly. The seat rail assembly comprises a lower rail which is fastened to a floor panel of a vehicle body and an upper rail which is operatively coupled with the lower rail. The upper rail can slide on the lower rail to move the seat to a desired position. Link means is disposed inside the seat rail assembly. The link means is connected to a knob provided to a side surface of the seat cushion and constitutes a part of a seat cushion pumping device for allowing a height of the seat cushion to be adjusted as desired.
Referring to FIG. 9, there is shown a schematic side view illustrating a state wherein a conventional seat cushion pumping device is applied to a seat cushion of a vehicle. A seat has a seat back and a seat cushion 2. The conventional seat cushion pumping device designated by the reference numeral 20 includes a front knob 4 and a rear knob 5 which are provided to a side surface of the seat cushion 2. Link means positioned below the seat cushion 2 is connected to the front and rear knobs 4 and 5. By rotating, like a dial, the front and rear knobs 4 and 5 in clockwise and/or counterclockwise directions, the link means can be lifted or lowered to adjust a height of the seat cushion 2.
The front and rear knobs 4 and 5 have their respective operating gears 6. The operating gears 6 are meshed with sector gears 11 and 12 connected with front and rear legs 7 and 8 which support front and rear portions of the seat cushion 2, respectively.
Describing operations of the seat cushion pumping device 20 constructed as mentioned above, by rotating the front and rear knobs 4 and 5 in clockwise and/or counterclockwise directions, the sector gears 11 and 12 meshed with the operating gears 6 of the front and rear knobs 4 and 5 are rotated. As a result of this, the front and rear links 9 and 10 are moved to adjust a height of the seat cushion 2 by way of the front and rear legs 7 and 8, respectively.
The conventional seat cushion pumping device 20 suffers from defects in that, since the front and rear portions of the seat cushion 2 are separately adjusted in their heights, it is difficult to hold the front and rear portions of the seat cushion 2 at the same height.
Specifically, because the front and rear knobs 4 and 5 are rotated like a dial, a substantial amount of operating force is required, and thereby, inconvenience is caused upon using the seat cushion pumping device 20.
Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a seat cushion pumping device for a vehicle which is solely used to allow a height of an entire seat cushion to be easily adjusted with reduced operating force, thereby improving quality of a seat and ensuring convenience upon use.
In order to achieve the above object, according to the present invention, there is provided a seat cushion pumping device for a vehicle, adapted for adjusting a height of a seat cushion, comprising: a clutch section arranged between a clutch cover and one surface of a base member to generate operating force required for adjusting a height of the seat cushion; and a brake section arranged between a brake cover and the other surface of the base member to conserve operating force of the clutch section; wherein the clutch section includes a pair of clutch blocks accommodated in a clutch groove defined on one surface of the base member; a lever block interposed between the pair of clutch blocks to operate them; and a lever coupled with the lever block and having a lever spring; and wherein the brake section includes a link connection gear secured around a shaft extending through a shaft hole defined in the brake cover, and meshed with a gear of link means; an operating plate secured around the shaft while being positioned between the link connection gear and the base member, and accommodated in a brake groove defined on the brake cover, the operating plate having flattened portions and being defined at both ends of the flattened portion with a pair of inclined wedge-shaped grooves; power transmitting projections integrally formed on the other surface of the base member, and fitted into grooves defined on a circumferential outer surface of the operating plate to transmit operating force of the clutch section to the operating plate; brake pins each accommodated in a space defined between the inclined wedge-shaped groove and the brake cover to transmit operating force of the base member only in an operating direction and prevent operating force transmission in a reverse direction; brake springs each installed between two brake pins to be capable of fixedly maintaining the brake pins in the space defined between the inclined wedge-shaped groove and the brake cover; and pushing pins integrally formed at both sides of the power transmitting projections to free the brake pins when the lever is returned to its original position.